Pressure relief valve for electric storage batteries

Abstract

A valve for an electric storage battery, including a cap housing for being positioned in an access port in the battery, the cap housing having interior side walls defining a gas-flow orifice therethrough. A valve member is positioned in the gas-flow orifice of the cap housing, and comprises a valve body, including at least one vent defining a gas-flow passage from an upstream to a downstream side of the valve body, a resilient, radially-outwardly extending annular skirt positioned on the downstream side of the valve body in gas-flow communication with the vent, the skirt extending radially outwardly from the valve body in the downstream direction. The skirt has an outermost free end normally sealingly engaging the side walls of the cap housing defining the gas-flow orifice. The annular skirt and adjacent side walls of the cap housing define therebetween an annular recess in gas-flow communication with the vent. The recess progressively narrows in the downstream direction to a terminus at the outermost free end of the skirt. The skirt is adapted to be resiliently responsive to internal gas pressure in the recess acting on the skirt to disengage the side walls of the cap housing by radial, inward movement at a predetermined gas pressure in the battery to provide a gap between the free end of the skirt and the side walls of the cap housing for passing gas past the valve member and into the atmosphere.

I claim: 
     
       1. A valve for an electric storage battery, comprising: (a) a cap housing for being positioned in an access port in said battery;   (b) said cap housing having interior side walls defining a gas-flow orifice therethrough;   (c) a valve member positioned in the gas-flow orifice of the cap housing, said valve member comprising: (1) a valve body, including at least one vent defining a gas-flow passage from an upstream to a downstream side of said valve body;   (2) a resilient, radially-outwardly extending annular skirt positioned on the downstream side of said valve body in gas-flow communication with said vent, said skirt extending outwardly from said valve body in the downstream direction, said skirt having an outermost free end normally sealingly engaging the side walls of the cap housing defining the gas-flow orifice;   (3) said annular skirt and adjacent side walls of said cap housing defining therebetween an annular recess in gas-flow communication with said vent, said recess progressively narrowing in the downstream direction to a terminus at the outermost free end of said skirt;   (4) said skirt adapted to be resiliently responsive to internal gas pressure in said recess acting on said skirt to: (a) disengage the side walls of said cap housing by radial, inward movement at a maximum gas pressure in said battery to provide a gap between the free end of the skirt and the side walls of the cap housing for passing gas past said valve member and into the atmosphere;   (b) retain liquids in said battery by trapping any liquid in the gas stream against the outwardly extending skirt and return the liquid in the upstream direction to the battery through the vent in the valve body; and   (c) return rapidly to sealing engagement with the side walls of the cap housing upon reduction of said gas pressure to a value below the maximum gas pressure.       
     
     
       2. A valve according to claim 1, wherein said valve body includes a pair of diametrically-spaced vents extending through the valve body adjacent the outer periphery thereof. 
     
     
       3. A valve according to claim 1, wherein said valve body includes a plurality of annular ridges on outer walls thereof for sealingly positioning said valve body in the gas-flow orifice of the cap housing. 
     
     
       4. A valve according to claim 1, wherein said skirt defines an annular void radially inwardly thereof. 
     
     
       5. A valve according to claim 1, including flame arrester means positioned in said gas-flow orifice downstream of said skirt. 
     
     
       6. A valve according to claim 1, including screw threads formed in outer walls of said cap housing for mating with complementary screw threads formed in walls of the battery defining the access port. 
     
     
       7. An electric storage battery, comprising: (a) a battery case for containing gas-generating electrochemical means for producing an electric current, said battery case containing at least one access port;   (b) a valve positioned in said at least one access port, said valve comprising: (1) a cap housing for being positioned in an access port in said battery;   (2) said cap housing having interior side walls defining a gas-flow orifice therethrough;   (3) a valve member positioned in the orifice of the cap housing, said valve member comprising: (a) a valve body, including at least one vent defining a gas-flow passage from an upstream to a downstream side of said valve body;   (b) a resilient, radially-outwardly extending annular skirt positioned on the downstream side of said valve body in gas-flow communication with said vent, said skirt extending outwardly from said valve body in the downstream direction, said skirt having an outermost free end normally sealingly engaging the side walls of the cap housing defining the gas-flow orifice;   (c) said annular skirt and adjacent side walls of said cap housing defining therebetween an annular recess in gas-flow communication with said vent, said recess progressively narrowing in the downstream direction to a terminus at the outermost free end of said skirt;   (d) said skirt adapted to be resiliently responsive to internal gas pressure in said recess acting on said skirt to: (1) disengage the side walls of said cap housing by radial, inward movement at a maximum gas pressure in said battery to provide a gap between the free end of the skirt and the side walls of the cap housing for passing gas past said valve member and into the atmosphere;   (2) retain liquids in said battery by trapping any liquid in the gas stream against the outwardly extending skirt and return the liquid in the upstream direction to the battery through the vent in the valve body; and   (3) return rapidly to sealing engagement with the side walls of the cap housing upon reduction of said gas pressure to a value below the maximum gas pressure.         
     
     
       8. An electric storage battery according to claim 7, and including a plurality of access ports positioned in spaced-apart relation along an upper surface of said battery case, each of said access ports having a positioned therein a respective valve. 
     
     
       9. An electric storage battery according to claim 7, wherein said valve body includes a pair of diametrically-spaced vents extending through the valve body adjacent the outer periphery thereof. 
     
     
       10. An electric storage battery according to claim 7, wherein said valve body a plurality of annular ridges on outer walls thereof for sealingly positioning said valve body in the gas-flow orifice of the cap housing. 
     
     
       11. An electric storage battery according to claim 7, wherein said skirt defines an annular void radially inwardly thereof. 
     
     
       12. An electric storage battery according to claim 7, including flame arrester means positioned in said gas-flow orifice downstream of said skirt. 
     
     
       13. An electric storage battery according to claim 7, including screw threads formed in outer walls of said cap housing for mating with complementary screw threads formed in walls of the battery defining the access port. 
     
     
       14. A valve for an electric storage battery, comprising: (a) a valve body for being positioned in an opening in the battery and communicating with the interior of the battery, said valve body comprising: (1) at least one vent defining a gas-flow passage from an upstream to a downstream side of said valve body;   (2) a resilient, radially-outwardly extending annular skirt positioned on the downstream side of said valve body in gas-flow communication with said vent, said skirt extending outwardly from said valve body in the downstream direction, said skirt having an outermost free end normally sealingly engaging walls of the opening in the battery,   (3) said annular skirt and adjacent side walls of said opening defining therebetween an annular recess in gas-flow communication with said vent, said recess progressively narrowing in the downstream direction to a terminus at the outermost free end of said skirt;   (4) said skirt adapted to be resiliently responsive to internal gas pressure in said recess acting on said skirt to: (a) disengage the walls of the opening by radial, inward movement at a maximum gas pressure in said battery to provide a gap between the free end of the skirt and the walls of the opening for passing gas past said valve body and into the atmosphere;   (b) retain liquids in said battery by trapping any liquid in the gas stream against the outwardly extending skirt and return the liquid in the upstream direction to the battery through the vent in the valve body; and   (c) return rapidly to sealing engagement with the side walls of the cap housing upon reduction of said gas pressure to a value below the maximum gas pressure.       
     
     
       15. A valve according to claim 14, wherein said valve body includes a pair of diametrically-spaced vents extending through the valve body adjacent the outer periphery thereof. 
     
     
       16. A valve according to claim 14, wherein said skirt defines an annular void radially inwardly thereof. 
     
     
       17. A valve according to claim 14, including flame arrester means positioned in the opening of the battery downstream of said skirt. 
     
     
       18. A valve according to claim 14, including screw threads formed in walls of the battery defining the opening and mating with complementary screw threads formed in walls of the battery defining the access port. 
     
     
       19. An electric storage battery, comprising: (a) a battery case for containing gas-generating electrochemical means for producing an electric current, said battery case containing at least one opening communicating with the interior of the battery;   (b) a valve positioned in said at least one opening, said valve comprising: (1) a valve body positioned in the opening, said valve body comprising: (a) at least one vent defining a gas-flow passage from an upstream to a downstream side of said valve body;   (b) a resilient, radially-outwardly extending annular skirt positioned on the downstream side of said valve body in gas-flow communication with said vent, said skirt extending outwardly from said valve body in the downstream direction, said skirt having an outermost free end normally sealingly engaging the walls defining the opening in the battery;   (c) said annular skirt and adjacent walls of said opening defining therebetween an annular recess in gas-flow communication with said vent, said recess progressively narrowing in the downstream direction to a terminus at the outermost free end of said skirt;   (d) said skirt adapted to be resiliently responsive to internal gas pressure in said recess acting on said skirt to: (1) disengage the walls of said battery opening by radial, inward movement at a maximum gas pressure in said battery to provide a gap between the free end of the skirt and the walls of the opening for passing gas past said valve body and into the atmosphere;   (2) retain liquids in said battery by trapping any liquid in the gas stream against the outwardly extending skirt and return the liquid in the upstream direction to the battery through the vent in the valve body; and   (3) return rapidly to sealing engagement with the side walls of the battery opening upon reduction of said gas pressure to a value below the maximum gas pressure.         
     
     
       20. An electric storage battery according to claim 19, and including a plurality of openings communicating with the interior of the battery and positioned in spaced-apart relation along an upper surface of said battery case, each of said openings having a positioned therein a respective valve. 
     
     
       21. An electric storage battery according to claim 19, wherein said valve body includes a pair of diametrically-spaced vents extending through the valve body adjacent the outer periphery thereof. 
     
     
       22. An electric storage battery according to claim 19, wherein said valve body a plurality of annular ridges on outer walls thereof for sealingly positioning said valve body in the opening in the battery. 
     
     
       23. An electric storage battery according to claim 19, wherein said skirt defines an annular void radially inwardly thereof.